1. Field
An embodiment of the present invention relates to an exposure method using an exposure apparatus for producing micro devices such as flat panel display devices, e.g., liquid-crystal display devices, an exposure apparatus for carrying out exposure by the exposure method, a photomask used in the exposure method, and a method of manufacturing the photomask.
2. Description of the Related Art
A projection exposure apparatus for projecting a pattern of a mask (reticle, photomask, or the like) through a projection optical system onto a plate (glass plate, semiconductor wafer, or the like) coated with a photo-resist is used, for example, in production of semiconductor devices, liquid-crystal display devices, or the like. The projection exposure apparatus (steppers) have frequently been used heretofore to effect full-field exposure of a pattern of a reticle in each shot area on a plate by the step-and-repeat method. U. S. Pat. No. 5,729,331discloses an exposure apparatus of the step-and-scan method comprising a plurality of partial projection optical units arranged in a direction perpendicular to a scanning direction and arranged at predetermined intervals and in plural rows along the scanning direction, instead of one large projection optical system, and exposuring patterns of a mask on a plate by the respective partial projection optical units with scanning of the mask and plate and a plurality of partial projection optical units used are optical systems which forms an unmagnified(unit magnification) erecting image therein. Further , U. S. Pat. No. 6,512,573 discloses that the magnification of the projection optical units is 1.1× to 1.5× or more and is the enlargement magnification of 4×in examples.